Louisiana Republican Rep. Steve Scalise and South Dakota Republican Sen. John Thune introduced legislation on Tax Day that would make it easier for wealthy Americans like President Barack Obama and billionaire Warren Buffett to voluntarily pay more in taxes.

“If Warren Buffett and others truly feel like they’re still not paying enough in taxes, they can use this Buffett Rule to put their money where their mouth is and voluntarily send in more to pay down the national debt, rather than raising taxes on hard-working Americans,” Scalise said.

“Liberals in Congress and the White House continue to call for more revenue. Here is their chance, but the only prerequisite is that donations that come from the Buffett Rule Act are strictly voluntary and are used to pay down our massive debt, not to fund more irresponsible spending,” he added.

Americans can already donate more money to the Treasury. Scalise’s and Thune’s legislation, however, would add a box to IRS filing forms to make the process even easier.

“President Obama has signed over $1.7 trillion in tax hikes into law since taking office, and now is proposing another $1.1 trillion in new taxes in his budget, including his Buffett Rule tax hike, which will stifle job creation and economic growth,” Thune added in a statement.

“President Obama continues to advocate for higher taxes on American families and small businesses, yet we just learned that his effective income tax rate for 2012 was only 18.4 percent, far lower than the 40 percent top marginal rate he’s advocated for small businesses and 30 percent effective rate he’s advocated for millionaires,” he continued.

According to Thune, the Buffett Rule Act will make it easier for “taxpayers such as the president to pay what they believe is their ‘fair share.’”

Last year, the House passed the Buffett Rule Act of 2011. The Senate did not consider the legislation.

If the bill is passed, the box on the IRS forms would read: “By checking here, I signify that in addition to my tax liability (if any), I would like to donate the included payment to be used exclusively for the purpose of paying down the national debt.”